class Solution {
public:
    int change(int amount, vector<int>& coins) {
        vector<int> dp(amount + 1, 0);

        dp[0] = 1;
        for(int coin : coins)
        {
            for(int i = 1; i <= amount; ++i)  {
                if(coin <= i) {
                    dp[i] += dp[i - coin];
                }
            }
        }
        return dp[amount];

    }
};